I wrote a small QT application which does not more than painting strings to screen, its my first QT app so don't expect too much.

It prooves my estimates that the GF6600 system is about 4x slower than my old GF488Go powerd laptop.
Therefor this is NOT an KDE problem, nor related to badly written applications!

This benchmark uses the default font which is on all of my three systems Sans with size 10. If you plan to run it yourself make sure the window is completly ereased (minimize and show it to get this result). not-complete repaints will show with shorter times.

PS: Note that KDE seems to leave subpixel-AA enabled if you had it enabled but just disable the subpixel-checkbox in the subpixel-dialog (bug?).
Thats why I first believed that non-subpixel-AA is slow too. If you select subpixel-greyscale instead kde disables rgb-subpixel and its as fast as non-subpixel-AA.
Edit: This only affects KDE-3.4, KDE-3.5 sets subpixel-aa right if you disable the checkbox.